From 04e87dec281f45831ca5f8bb7511791f87023a54 Mon Sep 17 00:00:00 2001
From: Stefan Becker <chemobejk@gmail.com>
Date: Tue, 1 Apr 2014 17:09:14 +0300
Subject: [PATCH] ews: add 4th autodiscover type

The 3rd type introduced to fix problems with Office 365 in

    commit 0ba825ca063e3d94487ec518e9a1c3f5a722dd1c

was based on trial & error. It seems that sending a POST request to a
http:// autodiscover URL does not work for all accounts:

    https://sourceforge.net/p/sipe/discussion/688534/thread/d21ebf11/

After studying another M$ document it turns out that we are allowed to
also send a GET request to such an URL and will then receive a redirect
response.

I tested that this works for at least 2 different Office 365 accounts.
GET seems to be accepted for Office 365 accounts for which POST was also
working. So we now try GET first and only then we try POST.
---
 src/core/sipe-ews-autodiscover.c | 75 +++++++++++++++++++++++++++++++++++-----
 1 file changed, 66 insertions(+), 9 deletions(-)

diff --git a/src/core/sipe-ews-autodiscover.c b/src/core/sipe-ews-autodiscover.c
index 3aaaa7b9..25b1665d 100644
--- a/src/core/sipe-ews-autodiscover.c
+++ b/src/core/sipe-ews-autodiscover.c
@@ -24,6 +24,8 @@
  *
  *   - POX: plain old XML autodiscover
  *   - [MS-OXDSCLI]:     http://msdn.microsoft.com/en-us/library/cc463896.aspx
+ *   - Autdiscover for Exchange:
+ *                       http://msdn.microsoft.com/en-us/library/office/jj900169.aspx
  *   - POX autodiscover: http://msdn.microsoft.com/en-us/library/office/aa581522.aspx
  *   - POX redirect:     http://msdn.microsoft.com/en-us/library/office/dn467392.aspx
  */
@@ -46,12 +48,17 @@ struct sipe_ews_autodiscover_cb {
 	gpointer cb_data;
 };
 
+struct autodiscover_method {
+	const gchar *template;
+	gboolean redirect;
+};
+
 struct sipe_ews_autodiscover {
 	struct sipe_ews_autodiscover_data *data;
 	struct sipe_http_request *request;
 	GSList *callbacks;
 	gchar *email;
-	const gchar * const *method;
+	const struct autodiscover_method *method;
 	gboolean retry;
 	gboolean completed;
 };
@@ -250,15 +257,63 @@ static gboolean sipe_ews_autodiscover_url(struct sipe_core_private *sipe_private
 	return(FALSE);
 }
 
+static void sipe_ews_autodiscover_redirect_response(struct sipe_core_private *sipe_private,
+						    guint status,
+						    GSList *headers,
+						    SIPE_UNUSED_PARAMETER const gchar *body,
+						    gpointer data)
+{
+	struct sipe_ews_autodiscover *sea = data;
+	gboolean failed = TRUE;
+
+	sea->request = NULL;
+
+	/* Start attempt with URL from redirect (3xx) response */
+	if ((status >= SIPE_HTTP_STATUS_REDIRECTION) &&
+	    (status <  SIPE_HTTP_STATUS_CLIENT_ERROR)) {
+		const gchar *location = sipe_utils_nameval_find_instance(headers,
+									 "Location",
+									 0);
+		if (location)
+			failed = !sipe_ews_autodiscover_url(sipe_private,
+							    location);
+	}
+
+	if (failed)
+		sipe_ews_autodiscover_request(sipe_private, TRUE);
+}
+
+static gboolean sipe_ews_autodiscover_redirect(struct sipe_core_private *sipe_private,
+					       const gchar *url)
+{
+	struct sipe_ews_autodiscover *sea = sipe_private->ews_autodiscover;
+
+	SIPE_DEBUG_INFO("sipe_ews_autodiscover_redirect: trying '%s'", url);
+
+	sea->request = sipe_http_request_get(sipe_private,
+					     url,
+					     NULL,
+					     sipe_ews_autodiscover_redirect_response,
+					     sea);
+
+	if (sea->request) {
+		sipe_http_request_ready(sea->request);
+		return(TRUE);
+	}
+
+	return(FALSE);
+}
+
 static void sipe_ews_autodiscover_request(struct sipe_core_private *sipe_private,
 					  gboolean next_method)
 {
 	struct sipe_ews_autodiscover *sea = sipe_private->ews_autodiscover;
-	static const gchar * const methods[] = {
-		"https://Autodiscover.%s/Autodiscover/Autodiscover.xml",
-		"http://Autodiscover.%s/Autodiscover/Autodiscover.xml",
-		"https://%s/Autodiscover/Autodiscover.xml",
-		NULL
+	static const struct autodiscover_method const methods[] = {
+		{ "https://Autodiscover.%s/Autodiscover/Autodiscover.xml", FALSE },
+		{ "http://Autodiscover.%s/Autodiscover/Autodiscover.xml",  TRUE  },
+		{ "http://Autodiscover.%s/Autodiscover/Autodiscover.xml",  FALSE },
+		{ "https://%s/Autodiscover/Autodiscover.xml",              FALSE },
+		{ NULL,                                                    FALSE },
 	};
 
 	sea->retry = next_method;
@@ -268,11 +323,13 @@ static void sipe_ews_autodiscover_request(struct sipe_core_private *sipe_private
 	} else
 		sea->method = methods;
 
-	if (*sea->method) {
-		gchar *url = g_strdup_printf(*sea->method,
+	if (sea->method->template) {
+		gchar *url = g_strdup_printf(sea->method->template,
 					     strstr(sea->email, "@") + 1);
 
-		if (!sipe_ews_autodiscover_url(sipe_private, url))
+		if (!(sea->method->redirect ?
+		      sipe_ews_autodiscover_redirect(sipe_private, url) :
+		      sipe_ews_autodiscover_url(sipe_private, url)))
 			sipe_ews_autodiscover_request(sipe_private, TRUE);
 
 		g_free(url);
-- 
2.11.4.GIT